Living Environment Regents Review Practice Laboratory Skills Question 1
Sunday, 28 June 2009 12:50
A student observed a Paramecium under the low power objective of a microscope (100x) and then under high power (400x). The image of the Paramecium under low power, compared to the image of the same Paramecium under high power, would be
A)Smaller and in a darker field of view
B)Smaller and in a brighter field of view
C)Larger and in a darker field of view
D)Larger and in a brighter field of view
Correct Answer: Option B - Smaller and in a brighter field of view
As you increase magnification from low to high power, the image gets larger and because the lens is bigger, less light is allowed in under high power. Therefore, under low power the image is smaller but brighter.
Living Environment Regents Review Practice Laboratory Skills Question 3
Sunday, 28 June 2009 12:47
To study the structure of phloem and xylem tissue, sections can be prepared and observed under a:
B)Triple beam balance
Correct Answer: Option D – Microscope
To observe the small structures such as cells, tissues, etc., it would be necessary to observe them with an increase in magnification.
A centrifuge is equipment, driven by a motor that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis. The centrifuge works using the sedimentation principle, where the centripetal acceleration is used to evenly distribute substances of greater and lesser density. It can be used for viable counts, when shaking the culture e.g. yeasts, out of suspension.
A triple beam balance is a type of balance commonly used in the laboratory to determine the mass of items. Sliding weights called riders on three beams are used.
Incubator is a laboratory instrument used to maintain a bacterial culture at a particular temperature for a set length of time.
Living Environment Regents Review Practice Laboratory Skills Question 4
Sunday, 28 June 2009 12:46
A sample of food containing one type of a large molecule was treated with a specific digestive enzyme. Nutrient tests performed on the resulting products showed the presence of simple sugars, only. Based on these test results, the original large molecules contained in the sample were molecules of:
Correct Answer: Option B – Starch
Starch is a complex sugar found in food items consumed. When starch is broken down simple sugars are formed.
Proteins and DNA cannot be broken down into simple sugar.
Glucose is a simple sugar by itself which can be easily absorbed by the digestive system.
Living Environment Regents Review Practice Laboratory Skills Question 8
Sunday, 28 June 2009 12:42
When a plant cell in normal water is moved into a A0% salt solution, the cytoplasm and vacuole of the plant cell shrink. The reason for this change is:
A)More salt moving out of the cell than into the cell
B)More salt moving into the cell than out of the cell
C)More water moving into the cell than out of the cell
D)More water moving out of the cell than into the cell
Correct Answer: Option D - More water moving out of the cell than into the cell
The reason for movement of more water out of the cell than into it is the process of osmosis. Osmosis is the diffusion of water through a semi-permeable membrane, from a low concentrate solution (high water potential) to a highly concentrated solution (low water potential), up a solute concentration gradient. Hence, causing the cytoplasm and vacuole of the plant cell to shrink.
Living Environment Regents Review Practice Laboratory Skills Question 10
Sunday, 28 June 2009 12:40
A student formulated a hypothesis that cotton will grow larger bolls (pods) if magnesium is added to the soil. The student has two experimental fields of cotton, one with magnesium and one without. Which data should be collected to support this hypothesis?
A)Height of the cotton plants in both fields
B)Length of the growing season in both fields
C)Color of the cotton bolls in both fields
D)Diameter of the cotton bolls in both fields
Correct Answer: Option D - Diameter of the cotton bolls in both fields
The data directly providing information to test the hypothesis is the diameter of the cotton bolls. Hence, it is the information to be collected to support the hypothesis.
Height of the cotton plants, length of the growing season and color of the cotton bolls are irrelevant to the hypothesis. Hence, options A, B and C are incorrect.
We are not affiliated with, nor endorsed by, the New York State Education Department.
The information contained in this website is for general information purposes only. The information is provided by "Technology Strategies for Success" and while we strive to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.